Circular economy for explosives

Emulsion explosives are used for blasting in the civil sector, especially in quarries or tunnel construction. The long-established Swiss company Société Suisse des Explosifs (SSE), a manufacturer and service provider in the specialist field of civilexplosives and fine chemicals, and operates in the safety-critical application area of these explosives with a newly introduced circular economy system. Enabler is a special silo container design for viscous liquids of packaging groups II and III from SCHÄFER Container Systems, manufacturer of recyclable IBCs and special containers made of stainless steel.

In the specific application, SSE mixes or emulsifies ammonium nitrate with oil to form an emulsion. The emulsion is filled into the developed special containers with a capacity of 1000 litres and transported to the construction sites. At the construction site, this is transferred to a mobile explosives manufacturing unit. The mobile explosives manufacturing unit adds two further chemical components to pump the emulsion into the boreholes, where it becomes the explosive EMULGA after the gassing phase and is ignited. Emptied containers are returned to SSE in the Swiss town of Brig for cleaning, inspection and refilling.

The stainless steel silo containers with hazardous material approval are designed in such a way that forklift forks can drive under the entire surface of the container. This technology, known in the trade as a forklift tunnel, works like a guide rail. The advantage is increased stability andtilt resistance, a crucial safety aspect when transporting dangerous goods with IBCs.

For efficient emptying of the silo containers, a conical outlet was developed according to customer requirements, which can be operated with a DN80 stainless steel ball valve. This allows the emulsion –whose viscosity is similar to the consistency of honey at room temperature –to flow out quickly so that no usable residual emulsion remains in the container. On the one hand, this increases the efficiency of the raw material use, and on the other hand, it facilitates the fundamentally necessary container cleaning.

"After a long search for a supplier of robust, custom-made special containers made of stainless steel, which can withstand the harsh conditions on the construction site for many years, we decided on SCHÄFER Container Systems. The decisive factors for the choice were sustainability aspects, quality, technical advice, individual design and manufacturing expertise, but also the price-performance ratio and deliveryreliability," says Fabian Venetz, Director Operations at SSE Switzerland.